Canadian Rainbirds wrote:
A lot depends on wheel/brake size. I learned to drive in British Columbia and am quite comfortable with mountain driving.
Years ago we drove our 30' 1997 Triple E Commander, on a Ford 460 chassis down the Espinazo del Diablo (Devil's Backbone) in Mexico, from Durango to Mazatlan. From 6,000 feet up to 9,000 ft, down to 6000 then back to 9000 then to sea level.
At one of the very few places to pull off I stopped for a "rest" break. Bad mistake. With no air moving past the wheels the drums on the 16" rear wheels heated the brake fluid to the point that there was vapour instead of fluid in the brake system. I pulled out behind a bus and braked for the corner and the pedal went to the floor :E Fortunately I was still going slow enough that I could pull it into 1st gear. A lot of pumping on the brake pedal gave me a little (just enough) braking. After following the bus downhill and pumping like mad when needed I regained reasonable braking in about 20 minutes.
We now drive a small (32') diesel pusher with 22.5" wheels, airbrakes and a great Allison 6 speed an excellent cruise control and exhaust brake.
Since you didn't say when you had last had your brake fluid flushed, it seems like you rode the brake pedal too much. Just 5% moisture in your brake fluid system will lower the boiling point of your brake fluid to under 300 degrees.
If your brake fluid had been flushed every two years, as recommended but very seldom done by RV owners, then you never would have boiled the fluid as you rode the brakes down the hill.
The fact that you could pump the brake pedal to get a little brake pressure indicates that you had moisture/steam in the brake lines.
Proper brake maintenance and not riding the brakes on a descent is very important for any RV that travels in the mountains.
I am sure that the brakes and wheel size on each RV is designed by engineers to handle the gross vehicle weight of your coach, if maintained and used properly.
